Conversion of high-energy photons into electricity

ABSTRACT

Systems and methods for the conversion of energy of high-energy photons into electricity which utilize a series of materials with differing atomic charges to take advantage of the emission of a large multiplicity of electrons by a single high-energy photon via a cascade of Auger electron emissions. In one embodiment, a high-energy photon converter preferably includes a linearly layered nanometric-scaled wafer made up of layers of a first material sandwiched between layers of a second material having an atomic charge number differing from the atomic charge number of the first material. In other embodiments, the nanometric-scaled layers are configured in a tubular or shell-like configuration and/or include layers of a third insulator material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/087,283, filed Mar. 31, 2016, which is a continuation of U.S. patentapplication Ser. No. 13/521,220, filed Feb. 4, 2013, now U.S. Pat. No.9,324,897, which is a national stage entry of PCT Application No.PCT/US2011/020001, filed Jan. 1, 2011, which claims the benefit of U.S.Provisional Application No. 61/293,282, filed Jan. 8, 2010.

FIELD

The embodiments described herein relate generally to photonic energyconversion and, more particularly, to systems and methods thatfacilitate the conversion of energy from high-energy photons intoelectricity.

BACKGROUND INFORMATION

There exist many well-known devices that convert the energy of photonsin the optical range into electricity, such as, e.g., photovoltaic cells(‘solar cells’). These devices are generally made up of at least twomaterials (i.e. silicon-based semiconductors) with different physicalproperties, such as different electron affinities (see, P. Würfel, ThePhysics of Solar Cells, 1st Edition, Wiley-VCH (200)). When one of thematerials is illuminated by sunshine, solar photons excitephotoelectrons from a valence band into a conduction band, whichprovides electric mobility. The energy gap between valence andconduction bands is typically on the order of an electron-volt, which issimilar to the energy of the incident solar photons. The arrangement oftwo materials with different electron affinities gives rise to anelectric voltage across the material boundary, which may be tapped forelectric energy.

There are, however, no known devices for conversion into electricity ofenergy from photons operating in the high-energy photon regime such as,e.g., XUV, X and gamma rays. Such devices could be used in a wide rangeof applications—for example, such devices could be used as energyconverters for the conversion of high-energy photons emitted byradioactive materials such as, e.g., spent fission fuel rods, emittedfrom detonation sources such as, e.g., explosives, and emitted from hightemperature plasmas and beams of accelerated particles, and as devicesin space applications as power sources, shielding, and the like.Difficulties in providing such devices arise from the greatpenetrability of high-energy photons through matter, which is aconsequence of much less interaction of such photons with matter whencompared with visible light, and from the fact that for most materialsthe mean-free-path of electrons is typically many orders of magnitudeshorter than the mean-free-path of high-energy photons. As a consequenceof this disparity in mean-free-paths, electrons emitted from an atom ina material used to trap the high-energy photons tend to succumb torecombination while their energy converts to heat within the high-energyphoton trapping material.

Thus, it is desirable to provide systems and methods that wouldfacilitate the conversion of energy from high-energy photons intoelectricity.

SUMMARY

The embodiments described herein are directed to the conversion ofenergy from high-energy photons into electricity. The principleunderlying the embodiments provided herein is based on the ejection ofelectrons from an atom (including the ejection of deep seated innershell electrons from an atom of high atomic number (high-Z) materials)by high-energy photons. The ejected electrons carry kinetic energy,which can lead to the migration of the ejected electrons into differentregions of a device where the accumulation of the ejected electrons cancreate an electric potential that can then drive an external electriccircuit. The photon spectrum of interest includes photons in thenon-visible regime including, but not limited to, XUV rays, X-rays,gamma rays and the like.

The systems and methods provided herein utilize a series of materialswith differing atomic charges to take advantage of the emission of alarge multiplicity of electrons by a single high-energy photon via acascade of Auger electron emissions. In one embodiment, a high-energyphoton converter preferably includes a linearly layerednanometric-scaled wafer made up of a first plurality of layers of amaterial for absorbing high energy photons and emitting electronscombined with a second plurality of layers of other materials forabsorbing or collecting electrons. The material of the second pluralityof layers having an atomic charge number differing from the atomiccharge number of the material of the first plurality of layers. Thefirst and second plurality of layers are preferably stacked laterallyside-by-side (i.e., face-to-face), interposing one another, and orientedat a grazing (shallow) angle to the direction of the propagation of thehigh energy photons. In another embodiment, the nanometric-scaled layersare configured in a tubular or shell-like configuration. In yet anotherembodiment, the layers include a third plurality of layers of insulatormaterial.

The systems and methods described herein may be utilized in a wide rangeof applications—from energy detection and absorption, to energyconversion of high-energy photons in particle accelerators and fromother extremely hot matter (such as high temperature plasmas) and/ordetonation sources that emit copious high-energy photons (such asexplosives), energy capture of emissions of radioactive nuclear wastes(such as spent fission fuel rods), and space applications (such as powersources, shielding, and the like), as well as other applications readilyrecognizable to one skilled in the art.

Other systems, methods, features and advantages of the exampleembodiments will be or will become apparent to one with skill in the artupon examination of the following figures and detailed description.

BRIEF DESCRIPTION OF THE FIGURES

The details of the example embodiments, including structure andoperation, may be gleaned in part by study of the accompanying figures,in which like reference numerals refer to like parts. The components inthe figures are not necessarily to scale, emphasis instead being placedupon illustrating the principles of the invention. Moreover, allillustrations are intended to convey concepts, where relative sizes,shapes and other detailed attributes may be illustrated schematicallyrather than literally or precisely.

FIG. 1A is a schematic of a linearly layered nanometric-scaledhigh-energy photon converter element.

FIG. 1B is a schematic of an alternative linearly layerednanometric-scaled high-energy photon converter element.

FIG. 1C is a schematic of a high-energy photon converter comprising anarray of linearly layered nanometric-scaled converter elements shown inFIG. 1A.

FIG. 1D is a schematic of a high-energy photon converter comprising anarray of linearly layered nanometric-scaled converter elements shown inFIG. 1B.

FIG. 1E is a schematic of a high-energy photon converter circuit.

FIG. 1F is a schematic of an alternative high-energy photon convertercircuit coupled to an external circuit comprising a load.

FIG. 2A is a perspective view of a cylindrically layerednanometric-scaled high-energy photon converter element.

FIG. 2B is a perspective view of an alternative cylindrically layerednanometric-scaled high-energy photon converter element.

FIG. 2C is a perspective view of a high-energy photon convertercomprising an array of cylindrically layered nanometric-scaled converterelements shown in FIG. 2A.

FIG. 2D is an end view of a high-energy photon converter comprising anarray of cylindrically layered nanometric-scaled converter elementsshown in FIG. 2B.

FIGS. 2E, 2F and 2G are end views of high-energy photon converters withalternative geometric configurations.

FIG. 3 is a diagram illustrating the propagation characteristics ofincident high energy photons ν and the migrating characteristics ofelectrons e⁻ that are ejected from their atoms in a layer of material bythe incident high-energy photons ν.

FIG. 4A is a schematic of a converter tile comprising a plurality oflinearly stacked layers.

FIG. 4B is a perspective view of a converter tile comprising a pluralityof linearly stacked layers.

FIG. 5 is a schematic showing an assembly of the tiles depicted in FIGS.4A and 4B arranged along a conforming surface that intercepts and issubstantially perpendicular to a photon flux emitted from a photon fluxsource

FIGS. 6A, 6B and 6C are schematics showing an assembly of the tilesdepicted in FIGS. 4A and 4B arranged along conforming surfaces thatintercept and are substantially perpendicular to photon fluxes emittedfrom photon flux sources.

It should be noted that elements of similar structures or functions aregenerally represented by like reference numerals for illustrativepurpose throughout the figures. It should also be noted that the figuresare only intended to facilitate the description of the preferredembodiments.

DETAILED DESCRIPTION

Each of the additional features and teachings disclosed below can beutilized separately or in conjunction with other features and teachingsto produce systems and methods to facilitate the conversion of energyfrom high-energy photons into electricity. Representative examples ofthe present invention, which examples utilize many of these additionalfeatures and teachings both separately and in combination, will now bedescribed in further detail with reference to the attached drawings.This detailed description is merely intended to teach a person of skillin the art further details for practicing preferred aspects of thepresent teachings and is not intended to limit the scope of theinvention. Therefore, combinations of features and steps disclosed inthe following detail description may not be necessary to practice theinvention in the broadest sense, and are instead taught merely toparticularly describe representative examples of the present teachings.

Moreover, the various features of the representative examples and thedependent claims may be combined in ways that are not specifically andexplicitly enumerated in order to provide additional useful embodimentsof the present teachings. In addition, it is expressly noted that allfeatures disclosed in the description and/or the claims are intended tobe disclosed separately and independently from each other for thepurpose of original disclosure, as well as for the purpose ofrestricting the claimed subject matter independent of the compositionsof the features in the embodiments and/or the claims. It is alsoexpressly noted that all value ranges or indications of groups ofentities disclose every possible intermediate value or intermediateentity for the purpose of original disclosure, as well as for thepurpose of restricting the claimed subject matter.

The embodiments described herein are directed to the conversion ofenergy from high-energy photons (such as, e.g., photons with energypreferably in a range of about 100 eV or greater) into electricity. Theprinciple underlying the embodiments is based on the ejection ofelectrons from an atom (including the ejection of deep seated innershell electrons from an atom of high atomic number (high-Z) materials)by high-energy photons. The ejected electrons carry kinetic energy,which can lead to the migration of the ejected electrons into differentregions of a device where the accumulation of the ejected electrons cancreate an electric potential that can be tapped to drive an externalelectric circuit. The photon spectrum of interest includes photonspreferably in the non-visible regime including, but not limited to, XUVrays, X-rays, gamma rays and the like. The energy of such photons isorders of magnitude larger and, thus, the margin for thermalization ismuch greater (the theoretical Carnot coefficient is near unity), thanthe energy of photons in the visible regime. Because of the highincident photon energy, generally 100 eV or greater, the systems andmethods described herein are capable of extraordinarily high efficiencyof energy conversion, as compared with other standard energy convertersof photons, such as photoelectric devices (e.g. solar cells), or devicesbased on the thermoelectric effect (e.g., Seebeck effect).

As discussed in further detail below, the systems and methods used toharness this potentially high gain effectively channel the energies ofthe high-energy photons into an appropriate form of electric energy,which can then be tapped to drive an external circuit, and, thus, covera wide range of applications, including those where strong magneticfields are present (such that electron dynamics are characterized bygyromotion across the magnetic fields). As a result, the systems andmethods described herein may be utilized in a wide range ofapplications—from energy detection and absorption, to energy conversionof high-energy photons in particle accelerators, direct energyconversion of high-energy photons from other extremely hot matter (suchas high temperature plasmas) and/or detonation sources that emit copioushigh-energy photons (such as explosives), energy capture of emissions ofradioactive nuclear wastes (such as spent fission fuel rods), and spaceapplications (such as power sources, shielding, and the like), as wellas other applications readily recognizable to one skilled in the art.

The systems and methods provided herein utilize a series of layers ofmaterials with differing atomic charges to take advantage of theemission of a large multiplicity of electrons by a single high-energyphoton via a cascade of Auger electron emissions. In one embodiment, ahigh-energy photon converter preferably includes a linearly layerednanometric-scaled wafer made up of a first plurality of layers ofmaterials for absorbing high energy photons and emitting electronscombined with a second plurality of layers of other materials forabsorbing or collecting electrons emitted from the first plurality oflayers. The materials of the second plurality of layers having an atomiccharge number differing from the atomic charge numbers of the materialsof the first plurality of layers. In another embodiment, thenanometric-scaled layers are configured in a tubular or shell-likeconfiguration. The nanometric layers facilitate the segregation ofphotoelectrons from donor atoms. Utilizing these structures, theresultant converter may reduce the power flux incident on materials thatwould otherwise be directly exposed to high-energy photons, therebyreducing the amount of heating of these materials and may alsoameliorate the degradation of the materials that are otherwise subjectto severe high-energy photon irradiation damages.

Turning in detail to the figures, systems and methods for energyconversion of high-energy photons into electricity with high efficiencyare illustrated. For purposes of the foregoing discussion, the converterdevice or devices are assumed to be embedded in strong magnetic fieldsthat can decisively impact the electron orbits. However, as will beevident below, on the characteristic length scales of the device, theelectron orbital properties are minimally affected by the magneticfields (with strengths that are practically attainable) so that theembodiments are equally applicable to applications where there arelittle or no magnetic fields present, such as, e.g., spent fission fuelrod applications.

Referring to FIGS. 1A through 1F, embodiments of a photon energyconverter having a linear structure is shown. As depicted in FIG. 1A,the most basic building block or converter element 10 of a photon energyconverter having a linear structure is comprised of a first layer 12 oftype A material having a first atomic number Z₁ and preferablycomprising a high atomic number component, such as, for example, arefractory metal or metal oxide. The first layer 12 is preferablysandwiched between two layers 14 of type B material having a secondatomic number Z₂ differing from the atomic number of the first layer 12of type A material, and preferably comprising a metal that is typicallypreferably characterized by a lower atomic number than the atomic numberof the first layer 12 of type A material (i.e., Z₂<Z₁). As depicted inFIG. 1B, the basic building block 10 can optionally be enhanced by theaddition of an insulator layer 16 of type C material. An exemplary setof types A, B and C materials may include, but is not limited to:A=tungsten (W), B=aluminum (Al), C=insulator such as SiO2.Alternatively, the insulator layer might simply be free flowing Heliumthat can also act as a coolant. However, one skilled in the art willreadily recognize that other materials can be substituted consistentwith the spirit of the present invention.

In preferred embodiments depicted in FIGS. 1C and 1D, converters 11 and13 include a series or an array of the basic building blocks stackedlaterally side-by-side (i.e., face-to-face) until the theoreticalmaximum aggregate photon path-length spent by the photon in all type Alayers 12 is comparable to or larger than the mean free path of the highenergy photons ν to be absorbed by the type A material. As depicted inFIGS. 1C and 1D, one or more layers 14 of type B material interposeadjacent layers 12 of type A material, and, optionally, a layer 16 oftype C insulation material interposes adjacent layers 14 of type Bmaterial.

Stacking the building blocks or converter elements 10 side-by-sideprovides a geometry for the overall structure that is well suited toeffectively accommodate the electron emissions caused by the high energyphotons ν absorbed in the type A material. Because the polarization ofphotons Ē, as depicted in FIG. 3, is perpendicular to the direction ofpropagation of the photon ν, the direction of the ejected electron e⁻ isprimarily in a plane P_(e) (with an appropriately decaying angulardistribution away from that plane, but peaking on that plane)perpendicular to the direction of the propagation of the photons ν (butsuch plane contains the polarization of the photons ν). As depicted inFIGS. 1A and 1B, the layers 12 and 14 of the converter elements 10 arestacked side-by-side in a direction such that the normal vector to theboundary surfaces between layers is generally orthogonal to thedirection of the propagation of the photons ν. In one preferredconfiguration described below, the boundary surfaces between layers canbe aligned at a grazing (shallow) angle with the direction ofpropagation of the incident high-energy photon ν. As a result, theelectrons e⁻ that are ejected within the layers 12 of the type Amaterial from their atoms by the incident high-energy photons ν are ableto migrate generally orthogonally into the neighboring layers 14 of typeB material.

Central to the principle of each embodiment, and any variation thereof,is the requirement that the emitted photoelectrons e⁻ not be trappedand/or absorbed in the layer 12 of type A material, but rather beabsorbed in the layer 14 of type B material. To insure that the ejectedelectrons e⁻ are not trapped within the layer 12 of type A material andincrease the likelihood that the ejected electrons e⁻ escape or migratefrom the layer 12 of type A material into a layer 14 of type B material,the thickness, fi, of each layer 12 of type A material is preferablysmaller than or on the order of the length of the mean free path ofelectrons in such type A material. The thickness, l₂, of each layer 14of type B material is preferably larger than or on the order of thelength of the mean free path of electrons in the type B material.Preferably, the nanometric arrangement of the layers of theseembodiments is reflective of the intrinsic physical principles that theelectron mean free path in the type A material, l_(e)(Z₁), is not toodifferent from the electron mean free path in the type B material,l_(e)(Z₂), while at the same time the photon mean free path in the typeA material is much less than its mean free path in the type B material,i.e., l_(p)(Z₁)>>l_(p)(Z₂).

For example for 100 keV incident photons, typical layer thicknessdimensions for these systems include l₁ for type A material equal toapproximately 1 nm and l₂ for type B material equal to approximately 100nm, with l₃ for the optional type C material adjusted to prevent arcingbetween neighboring layers where necessary. For magnetic fields B up to10 T, these dimensions are less than the gyroradius ρ_(e) of theelectrons. Therefore, on these length scales the electrons are notmagnetized, but their dynamics are primarily in the collisional regime.As a result, the converter elements 10 or converters 11 and 13 discussedabove are also applicable to applications where magnetic fields areabsent or negligibly small.

The migration into the neighboring layers 14 of type B material ofelectrons e⁻ ejected from atoms within the layers 12 of type A materialby the incident high-energy photons ν leads to an accumulation of chargeand ultimately generates a potential between the layers 12 and 14 oftype A and B material. Referring to FIGS. 1E and 1F, all type A and typeB layers 12 and 14 are connected to circuits such that each type A layer12 and type B layer 14 acts as an individual electrode. As readilyapparent to one skilled in the art, there exists an almost infinitenumber of options and alternatives to connect the layers or groupings oflayers in parallel or serial fashion. The optimal arrangement of suchcircuitry is advantageously application determinable as a result. Forexample, individual layers 12 and 14 can be connected in a fashionwhereby each layer 12 of type A material is connected to one of thenearest layers 14 of type B material as depicted in FIG. 1E, or eachlayer 12 of type A material can be connected to one of the nearestlayers 14 of type B material that is separated from it by an insulatinglayer 16 of type C material as depicted in FIG. 1F. In theseconfigurations, the electrically coupled layers effectively formnano-batteries and the spontaneously formed electric potentialdifference is on the order of the kinetic energy of migrating electrons.The total voltage available to drive a load is equal to the voltage ofan individual nano-battery cell 15 or the sum of the series ofnano-battery cells 17 and 19. As depicted in FIG. 1F, an externalcircuit 20 comprising a load 22 is coupled to the nano-battery cells 17and 19, which are depicted as coupled in series but could be coupled inparallel. The load 22 may comprise an electrically drivable system orcomponent, an energy storage system, an electrical grid, or the like.

Alternatively, by adjusting the load resistance of the circuit betweenthe electrode layers 12 and 14, the steady state voltage can beexternally controlled and the thickness of the insulating layer 16 sizedaccordingly.

In another embodiment, the basic building block includes a cylindricaltube or shell configuration. As illustrated in FIG. 2A, a cylindricalconverter element 110 comprises a cylindrical core 112 of type Amaterial surrounded by a cylindrical tube or shell 114 of type Bmaterial. As depicted in FIG. 2B, it is again possible to optionallysurround each shell 114 of type B material with an insulating shell 116of type C material. In this cylindrical configuration the samedimensional rules apply to the various thicknesses, i.e., the radius ofthe cylindrical cores 112 of type A material is less than or on theorder of about half of the electron mean free path in type A material,about l_(e)(Z₁)/2, while the thickness of the shell 114 of type Bmaterial is on the order of the electron mean free path in material B,about l_(e)(Z₂).

The advantage of the cylindrical tube or shell arrangement of theconverter element 110 is the higher efficiency it affords in capturingthe emitted electrons as they are emitted with equal probability over anentire 360° azimuth. As depicted in FIG. 3 and described above,electrons e⁻ are ejected in a direction primarily in a plane P_(e) (withan appropriately decaying angular distribution away from that plane, butpeaking on that plane) perpendicular to the direction of propagation ofthe photon ν and parallel to the polarization (Ē) of the photons.Depending on the angle of polarization of the photon, the ejectedelectron e⁻ can be directed anywhere about the 360° azimuth and in suchcase the cylindrical arrangement of the cell leads to higher electroncapture in type B material and effectively a higher electron captureefficiency as compared to the linear configurations depicted in FIG. 1Athrough 1F.

Similar to the linear geometry converter described above, thecylindrical building blocks 110 are bundled to form aggregate structuresthat conform to the same physical size constraints as the lineargeometry converter. As an example, one particular stacking arrangement111 is depicted in FIG. 2C. Alternatively, as depicted in FIG. 2D, inanother stacking arrangement 113, insulating material 116 can fill thevoid spaces between adjacent converter elements or cells 110. Such voidspace can also serve as a conduit for circulating gas coolants, such aspressurized Helium. This forms an effective means of cooling because thephoton absorption by He is negligible over the photon energies ofinterest. Electrical connections are again similar to the lineargeometry configurations and likewise afford many different options inconnecting the layers or shells 112 and 114 of the building blocks 110.

Alternative geometric configurations are shown in FIGS. 2E, 2F and 2G.FIG. 2E shows a staggered linear stacked layered arrangement in whichlayers 112 of type A material are offset to be positioned adjacentlayers 114 of type B material. FIG. 2F shows a plurality of cores 112 oftype A material surround by type B material filing the void spaces 114between the cores 112. Although shown square shaped, the cores 112 couldbe circular, oval, or the like. FIG. 2G is similar to the configurationin FIG. 2D with the exception of the core 112 and shell layer 114 beingsquare shaped. In these cases the dimensioning of elements 112, 114 and116 conforms to the same constraints discussed in FIGS. 1A through 1Cand FIGS. 2A through 2D. The electron dynamics at the edges of thesquares are different, but aside from these edge effects the otherphysical properties are generally similar to the cylindrical cases.

The basic building block in either geometry, which as described above ismade up of up to three kinds of materials, is suitable to spontaneouslygenerate electron separation from the original site of donor atoms,which have been ionized by high-energy photons. This in turn gives riseto the generation of electric voltages between the layers and/or acrossthe optional insulator. As discussed above, such an arrangement can beelectrically connected to a circuit to do electric work or transmitpower from the converter. As a further variant, it should be noted thatone can also apply an external voltage (bias voltage) between theselayers, which provides further control over the electric properties andminimizes the potential for arching across any of the layers.

Referring to FIGS. 4A and 4B, in order to maximize the radiation exposedsurface area to insure that the incident high energy photon ν iscaptured by a layer 212 of type A material and does not simply passthrough a layer 214 of type B material, the stacked layers 212 and 214of type A and B materials, and the optional layer 216 of type Cinsulation material, of a converter tile or cell 200 are preferablytilted at a grazing (shallow) angle θ to the direction of propagation ofthe incident high-energy photon ν, which, for example, may be on theorder of about 1/100 radian. Tilting the converter tile 200 also assuresadequate cooling of the bombarded type A material and minimizes thethickness of each individual layer 212 of type A material (relative tothe mean free path of electrons) as well as the aggregate effectivethickness of all layers 212 of type A material in the entire converterassembly. Tilting the converter tile 200 at a grazing angle also causesthe electrons to be ejected predominantly perpendicularly to the surfaceof the type A material. It also reduces the necessary number of repeatedlayers per tile 200 by a factor of approximately 1/θ, as thetransmission distance in the type A material is enhanced by the samefactor over the case where the orientation angle Φ of the surface oftile 200 is organized normal to the propagation direction of theincident high energy photon ν. It also maximizes the escape of electronsinto the adjacent layer of type B material.

In an alternative embodiment, the converter tile 200 depicted in FIGS.4A and 4B comprises a plurality of cylindrical converter elements 110(shown in FIGS. 2A and 2B) stacked side by side and tilted at a grazingangle θ.

Referring to FIG. 4B, in order to effectively absorb most of thehigh-energy photons with energy on the order of about 100 keV, theheight H of the device needs to extend to orders of length of about onecentimeter (1 cm) in the general direction of the predominant photonpropagation. This is due to the desire to intercept the entire photonflux with type A material with sufficient aggregate thickness in thephoton propagation direction. Since the thickness of each layer of typeB material is typically much greater than the thickness of each layer oftype A material (l₁<<l₂), the total height H of the complete stack ofbuilding blocks projected onto the direction of the photon flux needs tobe much greater than the mean free path of the particular photons in thetype A material to insure that high energy photons encounter type Amaterial over an aggregate distance greater than their mean free path insuch material. The height of the complete stack of building blocks,therefore, should exceed the mean free path of photons in the type Amaterial by a factor of at least l₂/l₁ or, in the case of inclusion ofthe insulating layer, by a factor of at least (l₃+l₂)/l₁.

As mentioned above, the overall arrangement also provides effectivecooling of the converter materials as they are heated by photonabsorption as well as subsequent electron heating. The cooling isfacilitated because the total surface area in the present embodiment, asdepicted in FIG. 4A, is enlarged compared to a simple arrangement oflayering the stacks at an orientation angle Φ perpendicular to thedirection of the incident photon flux by a factor of 1/θ. It is alsopossible to flow pressurized gas coolant through pipes built into thestructure or simply connect the stacks to heat sinks. One skilled in theart would readily recognize that there may be many other ways to enhancethe cooling and that particular implementations will be dictated by thespecific application.

An assembly 220 of the converter tiles 200, as depicted in FIG. 5, canbe arranged along a conforming surface 230 that intercepts and issubstantially perpendicular to the photon flux 242 emitted from a givenphoton flux source 240. This configuration provides flexibility andadaptability to a wide spectrum of applications that might require (orbenefit from) energy generation from the emitted photon flux.

Other examples of overall geometries of typical applications aredepicted in FIGS. 6A, 6B and 6C. FIG. 6A shows a plasma containmentsystem 300 that includes a cylindrical chamber 330 having a surface 334that intercepts and is substantially perpendicular to a photon flux 342emitted from a source 340 of photon flux shown as hot plasma. Thecontainment system 300 further comprises a magnetic field generator 332positioned along the cylindrical chamber 330 and an array 332 ofconverter tiles 200 affixed along the surface 334 of the chamber 330.Each of the tiles is oriented at a grazing angle to the direction ofpropagation of the incident high-energy photons ν of the photon flux342. FIG. 6B shows a containment system 400 that includes a cylindricalcontainer 430 having a surface 434 that intercepts and is substantiallyperpendicular to a photon flux 442 emitted from a source 440 of photonflux shown as hot plasma or expend fission fuel rods. The containmentsystem 400 further comprises an array 432 of converter tiles 200 affixedabout the surface 434 of the container 430. Each of the tiles isoriented at a grazing angle to the direction of propagation of theincident high-energy photons ν of the photon flux 442. FIG. 6C shows aparticle acceleration system 500 that includes a cylindrical tube 530having a surface 534 that intercepts and is substantially perpendicularto a photon flux 542 emitted from a source 540 of photon flux shown asan accelerated particle beam. The accelerator system 500 furthercomprises a magnetic field generator 532 positioned along thecylindrical tube 530 and an array 532 of converter tiles 200 affixedalong the surface 534 of the tube 530. Each of the tiles is oriented ata grazing angle to the direction of propagation of the incidenthigh-energy photons ν of the photon flux 542.

In each case the emitted high energy photons encounter type A materialover an aggregate distance greater than their mean free path in suchmaterial A. This assures their proper absorption by atoms within thetype A layers and ultimately amplified conversion of photon current toelectron current. Surrounding the flux emitting volume, the type Amaterial densely covers all high energy photon flux exposed surfaceareas, while at the same time allowing for cooling and electricalconnections.

It should be noted that in accordance with the embodiments providedherein, multiple electrons are emitted from a particular atom in thetype A material due to absorption of high-energy photons. This isbecause an electron that is knocked out from a particular deepelectronic inner shell state creates a vacancy, which is quickly filledby the Auger process, which in turn triggers secondary and tertiaryAuger processes, or a cascade of processes. In addition, secondaryphoton re-emission can trigger further such processes in neighboringatoms. Accordingly, one photon can in principle trigger the aggregateemission of some 100 electrons (and sometimes more). Therefore, thismultiple ionization provides double benefits. First, it serves tomultiply the amount of electrons per original incident photon by afactor of 100 to 1,000, which leads to high current amplification.Second, it serves to reduce the electron energies from tens of keV tomere tens of eV. Thus, the voltage generated is manageable relative tobreak down concerns. This provides enhanced conversion of photon energyto electricity (its charge and current), while it also minimizes heatingof the target. In fact the system serves as an efficacious coolant meansby removing most of the deposited photon energy (via electric energy)from the material that sits next to the photon source and readilytransports the converted energy away to remote sites not in the vicinityof the radiation.

The example embodiments provided herein, however, are merely intended asillustrative examples and not to be limiting in any way. Moreover, oneskilled in the art will readily recognize that similar systems can beequally adapted to photons of different energies with appropriatemodification of parameters.

In the foregoing specification, the invention has been described withreference to specific embodiments thereof. It will, however, be evidentthat various modifications and changes may be made thereto withoutdeparting from the broader spirit and scope of the invention. Forexample, the reader is to understand that the specific ordering andcombination of process actions shown in the process flow diagramsdescribed herein is merely illustrative, unless otherwise stated, andthe invention can be performed using different or additional processactions, or a different combination or ordering of process actions. Asanother example, each feature of one embodiment can be mixed and matchedwith other features shown in other embodiments. Features and processesknown to those of ordinary skill may similarly be incorporated asdesired. Additionally and obviously, features may be added or subtractedas desired. Accordingly, the invention is not to be restricted except inlight of the attached claims and their equivalents.

What is claimed is:
 1. A detector for detecting high energy photonemissions, comprising a plurality of layers of a first material thatabsorbs high energy photons and emits electrons ejected from an atom inan individual layer of the plurality of layers of the first material bya high energy photon absorbed in the individual layer of the pluralityof layers of the first material, each layer of the plurality of layersof the first material having a thickness measured along the direction ofthe emitted electrons that is less than the length of the mean free pathof the emitted electrons in the first material, wherein the thickness ofeach layer of the plurality of layers of the first material measuredalong the direction of propagation of a high energy photon is less thanthe length of a mean free path of the high energy photon in the firstmaterial, wherein the wavelengths of the high energy photons are in thenon-visible regime, and wherein a plurality of layers of the pluralityof layers of a first material encountered by a high energy photon alongthe direction of propagation of the high energy photon having anaggregate thickness measured along the direction of propagation of a thehigh energy photon that is greater than the length of a mean free pathfor the high energy photon in the first material, and a plurality oflayers of a second material that collects electrons emitted from theplurality of layers of the first material and electrically coupled tothe plurality of layers of the first material, each layer of theplurality of layers of the second material having a thickness greaterthan the length of the mean free path in the second material of theelectrons emitted from the plurality of layers of the first material,wherein one or more layers of the plurality of layers of the secondmaterial interposing adjacent layers of the plurality of layers of thefirst material, wherein the direction of propagation of the high energyphotons is substantially orthogonal to a normal vector to a boundarysurface between adjacent layers of the plurality of layers of the firstand second material, and wherein the electrons emitted from the firstmaterial are emitted in a direction perpendicular to the direction ofpropagation of the high energy photons.
 2. The detector of claim 1further comprising a plurality of layers of a third material, each layerof the plurality of layers of the third material interposing adjacentlayers of the one or more layers of the plurality of layers of thesecond material.
 3. The detector of claim 1 wherein adjacent layers ofthe plurality of layers of the first and second material are stackedface-to-face.
 4. The detector of claim 1 wherein each layer of theplurality of layers of the first material is configured as a cylindricalcore and each layer of the plurality of layers of the second material isconfigured as a cylindrical shell concentrically disposed about thecylindrical core of the first material, wherein the radius of thecylindrical core is less than ½ the length of the mean free path of theemitted electrons in the first material.
 5. The detector of claim 4further comprising a plurality of layers of a third insulating materialconfigured as a cylindrical shell concentrically disposed about thecylindrical shell of the second material.
 6. The detector of claim 1wherein the first material comprises a high atomic charge numbercomponent.
 7. The detector of claim 6 wherein the high atomic chargenumber component is a refractory metal or metal oxide.
 8. The detectorof claim 6 wherein the high atomic charge number component is tungsten.9. The detector of claim 1 wherein the atomic charge number of thesecond material differs from the atomic charge number of the firstmaterial.
 10. The detector of claim 1 wherein the atomic charge numberof the second material is lower than the atomic charge number of thefirst material.
 11. The detector of claim 1 wherein the second materialis a metal.
 12. The detector of claim 11 wherein the metal is aluminum.13. The detector of claim 1 wherein each of layers of the plurality oflayers of the first material is sandwiched between two layers of theplurality of layers of the second material.
 14. The detector of claim 1wherein the high energy photons absorbable by the first material haveenergies in the range of about 100 eV or greater.
 15. The detector ofclaim 1 wherein the high energy photons absorbable by the first layer ofmaterial include X, XUV or gamma rays.
 16. The detector of claim 1wherein the plurality of layers of the first and second material arecoupled to a circuit having a load.
 17. The detector of claim 16 whereinthe load is an electrically drivable component.
 18. A detector fordetecting high energy photon emissions, comprising a plurality of layersof a first material that absorbs high energy photons and emits electronsejected from an atom in an individual layer of the plurality of layersof the first material by a high energy photon absorbed in the individuallayer of the plurality of layers of the first material, each layer ofthe plurality of layers of the first material having a thicknessmeasured along the direction of the emitted electrons that is less thanthe length of the mean free path of the emitted electrons in the firstmaterial, wherein the thickness of each layer of the plurality of layersof the first material measured along the direction of propagation of ahigh energy photon is less than the length of a mean free path of thehigh energy photon in the first material, wherein the wavelengths of thehigh energy photons are in the non-visible regime, and wherein aplurality of layers of the plurality of layers of a first materialencountered by a high energy photon along the direction of propagationof the high energy photon having an aggregate thickness measured alongthe direction of propagation of a the high energy photon that is greaterthan the length of a mean free path for the high energy photon in thefirst material, a plurality of layers of a second material that collectselectrons emitted from the plurality of layers of the first material andelectrically coupled to the plurality of layers of the first material,each layer of the plurality of layers of the second material having athickness greater than the length of the mean free path in the secondmaterial of the electrons emitted from the plurality of layers of thefirst material, wherein one or more layers of the plurality of layers ofthe second material interposing adjacent layers of the plurality oflayers of the first material, wherein the direction of propagation ofthe high energy photons is substantially orthogonal to a normal vectorto a boundary surface between adjacent layers of the plurality of layersof the first and second material, and wherein the electrons emitted fromthe first material are emitted in a direction perpendicular to thedirection of propagation of the high energy photons, and a plurality oflayers of a third material, each layer of the plurality of layers of thethird material interposing adjacent layers of the one or more layers ofthe plurality of layers of the second material wherein the thirdmaterial is SiO2.